Temporomandibular disorders (TMD's) are a group of pain conditions characterized by pain in the muscles of mastication and/or the temporomandibular joint. Population prevalence of TMD is about twice as high in women as in men and it is more frequently reported during the reproductive years. About 80% of clinic cases presenting for TMD pain are female. The reasons for the gender discrepancy may involve biologic, psychologic and social factors such as hormonal differences, differences in pain perception, or differences in pain expression or health care utilization. Some data suggest that TMD patients demonstrate greater sensitivity to ischemic pain delivered using the submaximal effort tourniquet test. Sensitivity to the stimulus may vary across the menstrual cycle and be positively correlated with blood pressure during the luteal and follicular phase of the menstrual cycle. Experimental pain sensitivity has been shown to be inversely related to blood pressure in normal males, but this relationship is considerably less clear in females and pain patients. The investigators propose to further assess the discriminative ability of the submaximal effort tourniquet test and to study systematically the interrelationships between blood pressure, menstrual cycle phase, and ischemic pain sensitivity in TMD patients and pain free controls. They intend to augment an ongoing project funded by the NIDCR and ORWH by adding the submaximal effort tourniquet test as well as resting and reactivity blood pressure measurement during experimental pain stimuli. The study will assess blood pressure variability and variability in responses to ischemic pain at critical points (menses, ovulatory, mid-luteal and late luteal/premenstrual phases) across three consecutive ovulatory cycles in female TMD cases and appropriate controls, to ascertain the extent to which variability in blood pressures and pain may be attributable to female gender, hormonal status, and/or presence of clinical TMD pain. Thus, the proposed study will determine the discriminative ability of the tourniquet test for distinguishing female and male TMD patients from same-sex, pain free controls and evaluate the interrelationships between menstrual cycle, blood pressure and pain.